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Chemical solution deposition (CSD) is a versatile method to fabricate oxide films. Here, the structure and local variations in the chemical composition of BaTiO 3 (BTO) films prepared by CSD on (100), (110), and (111) SrTiO 3 (STO) substrates were examined by transmission electron microscopy. The films were shown to be epitaxial and the relaxation of the films occurred by the formation of edge dislocations at the substrate–film interfaces. The Burgers vectors of the dislocations were determined to be a ⟨ 010 ⟩ , a [ 1 1 ¯ 0 ] and a [ 001 ] , and a ⟨ 110 ⟩ for the (100), (110), and (111) films, respectively. Due to the difference in thermal expansion between STO and BTO, the films are demonstrated to be under tensile strain. Furthermore, the boundaries between each deposited layer in the BTO films were found to be Ba-deficient in all cases. In the case of the (111) oriented film, defects like an anti-phase boundary or a thin layer with a twinned crystal structure were identified at the boundary between each deposited layer. Moreover, a larger grain was observed at the film surface with a twinned crystal structure. The interdiffusion length of A-cations at the STO–BTO interface, studied by electron energy-loss spectroscopy, was found to be 3.4, 5.3, and 5.3 nm for the (100), (110), and (111) oriented films, respectively. Interdiffusion of cations across the STO–BTO interface was discussed in relation to cation diffusion in bulk BTO and STO. Despite the presence of imperfections demonstrated in this work, the films possess excellent ferroelectric properties, meaning that none of the imperfections are detrimental to the ferroelectric properties. [ABSTRACT FROM AUTHOR]

Rapid quenching of fused mixtures of nitride compounds at very high pressures yields glasses formed on the Li(sub 3)N-Ca(sub 3)N(sub 2)-P(sub 3)N(sub 5) system. Physical properties such as refractive index and hardness of oxide glasses is increased by the addition of nitrides. The addition of ionic nitrides enhances the physical properties.

The morphology and ontogeny of the postcranial skeleton were studied in three developmental series and a number of postmeta-morphic specimens of American shad, equaling more than 180 specimens. Specimens were cleared and stained with alcian blue to identify cartilage structures and with alizarin red to examine bone development. Histological preparations were made to confirm several questionable cases of endochondrial ossification. Pre-hatch embryos lack postcranial skeletal elements although the finfolds and pectoral fin buds are present. By the end of the yolk-sac larval period the hypurals in the caudal fin begin to form, rapidly followed by the development of the dorsal and anal fins. As the medial fins form, the elements of the vertebral column develop. The paired pelvic fins are the last to form during the metamorphic change of larvae into juveniles. The developmental sequence was divided into a series of stages that will allow future comparisons with other closely related species. Our results also show that 1) the uroneurals in shad are endochondrial in origin like other teleosts, 2) hypural 1 is autogenous because of incomplete ossification, 3) mineralization of protocentra occurs in an anterior to posterior direction resulting in chordacentra, and 4) development of the skull and anterior vertebral column exhibit several modifications associated with the otophysic system and sound transmission.

Ferroelectric BaTiO3 is widely used in capacitors, but the low Curie temperature limits a further use of BaTiO3. In this work we present an aqueous chemical solution deposition (CSD) route for BaTiO3 thin films, demonstrating that organic solvents are not required for CSD. Textured BaTiO3 thin films were deposited on SrTiO3 substrates. The in-plane dielectric properties were investigated using interdigitated electrodes and ferroelectric switching was observed up to 160±5 °C. The increased Curie temperature is proposed to result from thermal strain due to a mismatch in thermal expansion coefficient between the film and the substrate, and is in good agreement with the theory of strain engineering in BaTiO3. Finally, the decomposition and crystallization of BaTiO3 during thermal treatment were determined by the combination of thermal analysis, IR spectroscopy and X-ray diffraction of powder prepared from the solution. [ABSTRACT FROM AUTHOR]

The electronic properties of MoO3 and reduced molybdenum oxide phases are studied by density functional theory (DFT) alongside characterization of mixed phase MoOx films. Molybdenum oxide is utilized in compositions ranging from MoO3 to MoO2 with several intermediary phases. With increasing degree of reduction, the lattice collapses and the layered MoO3 structure is lost. This affects the electronic and optical properties, which range from the wide band gap semiconductor MoO3 to metallic MoO2. DFT is used to determine the stability of the most relevant molybdenum oxide phases, in comparison to oxygen vacancies in the layered MoO3 lattice. The non-layered phases are more stable than the layered MoO3 structure for all oxygen stoichiometries of MoOx studied where 2 ≤x ＜ 3. Reduction and lattice collapse leads to strong changes in the electronic density of states, especially the filling of the Mo 4d states. The DFT predictions are compared to experimental studies of molybdenum oxide films within the same range of oxygen stoichiometries. We find that whilst MoO2 is easily distinguished from MoO3, intermediate phases and phase mixtures have similar electronic structures. The effect of the different band structures is seen in the electrical conductivity and optical transmittance of the films. Insight into the oxide phase stability ranges and mixtures is not only important for understanding molybdenum oxide films for optoelectronic applications, but is also relevant to other transition metal oxides, such as WO3, which exist in analogous forms. [ABSTRACT FROM AUTHOR]

The effect of Mo-substitution was investigated for the LaCoxNiyMozO3 system, obtaining single-phase perovskite for Mo-substitutions up to 20 at%. The crystal structure of the perovskite changed from rhombohedral, orthorhombic to monoclinic with increasing Mo-content. The thermal expansion was suppressed by Mo-substitution, while the electrical conductivity was also suppressed, but remained relatively high. [ABSTRACT FROM AUTHOR]